A modern building structure is constructed with an exterior cladding, or primary weather barrier, that provides a first line of defense against the elements and also provides a good appearance for the building structure. Interior to and generally supporting the exterior cladding there is a building frame, typically made of dimensioned lumber (longitudinal elements) mechanically attached together, with sheets of plywood or particle board mechanically attached to the exterior side of these longitudinal elements. The dimensioned lumber may go by industry standard terminology of 2 by 4 s, 2 by 6 s, 2 by 8 s, or even wider elements, depending on the load that must be born, and other factors. Wall board is typically mechanically fastened to the interior side of the longitudinal elements, thereby defining a “wall cavity” between the exterior sheathing and the interior wall board. A secondary weather barrier, that is generally water resistant and is typically made of polymer sheeting, such as Tyvek®, or building paper, is mechanically attached to the building frame. These sheets are generally arranged as shingles are, with each upper piece of sheeting overlapping on the outside of the sheeting immediately below. With this arrangement water does not have any chance of penetrating through to the wall cavity of the building as it flows downward.
A weakness in this scheme is created by electrical receptacles and light fixtures, for example for an exterior electrical junction box, which must go through the exterior cladding and the secondary weather barrier. The general scheme for these (until recently) has been to caulk around them to create a seal against the exterior cladding. This is ineffective, however, as cycles of thermal expansion over the years, and the assault of the elements can weaken the seal, leading to water penetrating into the wall cavity. More recently, a line of products, have been introduced, with a shell defining a cavity and a brim, stretching out from a position to the rear of the front of the shell. These are installed, over the electrical junction boxes, with tape or mechanical attachment. Unfortunately, the portion of the shell extending out from the brim location may not protrude out far enough (or may protrude too far) from the brim to be flush with the edge of the exterior cladding, which differs in thickness from job to job. An installation flush with the exterior surface is desirable for appearance and ease of use of an outlet. Also, water that enters the cavity may work its way between the shell extension and the electrical junction box or to the rear of the electrical junction box and exit through the holes in the electrical junction box that accommodate the electrical wires to the electrical receptacle, thereby entering the wall cavity and potentially causing water damage. Also, it is possible that in places the inner surface of the exterior cladding will rest against the secondary weather barrier and the brim. In this case, water may become trapped and instead of flowing downward sit and cause decay and potential mold growth on the interior of the exterior cladding. Finally, the electrical junction box typically requires a further bracket, or fasteners, for secure attachment to the building frame.